JPS59206776A - Method and apparatus for testing printed circuit board - Google Patents

Abstract

PURPOSE:To test simply, rapidly and accurately the existence of disconnection of a pattern and conduction or short-circuit between patterns by press-contacting an anisotropic conductive rubber sheet-like substance to both sides of the surfaces of a printed circuit board to be tested and supplying current through a testing tool circuit plate and a contact probe. CONSTITUTION:The anisotropic conductive rubber sheet-like substance is set up on both sides of the surface of the printed circuit board 1 to be tested, the contact proobe 4 is previously fixed on a metallic plate through an insulating plate 5, the printed circuit board and the conductive rubber sheet-like substance 3 are unitedly adhered and pressed, and then current is supplied to the contact proobe 4, so that current is made flow into the circuit on the printed circuit board 1 through a pad 10, a circuit detecting terminal 9 and the conductive rubber sheet- like substance 3. Thus, the existence of conduction of a pattern and short-circuit between the patterns is tested simply, rapidly and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for inspecting a printed wiring board and an apparatus therefor, and more specifically, the present invention relates to a method for inspecting a printed wiring board and an apparatus for inspecting the same. By tightening the test jig and applying electricity through the circuit board and the contact probes, it is possible to inspect the presence or absence of pattern disconnections or continuity shorts between patterns on the printed wiring board extremely simply, quickly, and with high precision. The object of the present invention is to provide a printed wiring board inspection method and apparatus.

Conventionally, the method for inspecting the presence or absence of pattern breakage or conductive short circuit between patterns on a printed wiring board is to simply fix contact probes to the upper and lower insulating plates (b) as shown in Figure 1, and then attach them to the printed wiring board. This was accomplished by using a device that was inserted into the edge of the pattern in step 1) and energized.

However, the contact probe marks in the above conventional method usually have a diameter of 1.5 # to 2.5 #. Since the size is about Off, 2. It is extremely difficult to inspect the presence or absence of electrically conductive defects between bats in a fine pattern with an interval smaller than Off.

Therefore, the present applicant previously proposed an invention relating to a printed wiring board and an apparatus for inspecting the same as shown in FIG. 2 in Japanese Patent Application No. Sho.

The invention described above has 2# different directions on both the front and back sides of the printed wiring board to be tested for continuity! An inspection jig circuit board for clamping an electric rubber sheet-like object is provided, the jig circuit board includes at least an external draw-out connector pad electrically connected to an external draw-out pattern, and the external draw-out pattern is The present invention relates to a method and apparatus for inspecting a printed wiring board using a device formed on the surface of a jig circuit board and arranged so that the printed wiring board and the jig circuit board face each other directly.

However, devices using the above-mentioned external connector pads always require soldering to attach the connectors, so preparations for attaching the connectors must be carried out in advance for each type of printed wiring board pattern to be tested for continuity. It takes a long time to process, and is not necessarily suitable for producing a wide variety of products in small quantities, such as printed wiring boards.

On the other hand, when installing the connector, it is necessary to install the jig on the circuit board by approximately 0.8~1.
．． Since holes of approximately Qtsw must be drilled, the area occupied by the pattern is reduced, and furthermore, the degree of freedom in pattern design is restricted due to the attachment of the connector, making it difficult to refine the pattern.

The present invention eliminates and improves the above drawbacks of the conventional method, and instead of attaching the connector with solder, a contact probe is fixed to an insulating plate, etc., and this is connected to a pad for the contact probe on a jig circuit board. This feature eliminates the need for preparatory work such as soldering connectors, allowing for easy and quick inspection of printed wiring boards, and eliminating the need for drilling holes for connector installation, which improves the degree of freedom in pattern design. The present invention provides a method and apparatus for inspecting fine patterned printed wiring boards.

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 3 is a sectional view showing an example of the printed wiring board inspection method and apparatus of the present invention.

In this drawing, (1) is a printed wiring board, and since the present invention is for inspecting the presence or absence of disconnection of patterns or continuity short circuits between patterns in various printed wiring boards, it is a printed wiring board with a complicated pattern. In particular, even various high-density printed wiring boards such as fine double-sided through-hole boards and hybrid boards can be inspected. This makes it possible to easily increase the number of contact probe pads corresponding to an increase in the number of detection ends of a printed wiring board with a high density and complicated circuit, and the position of the pads can also be changed. By not being restricted.

Next, (2) is a test jig circuit board, which has a detection end that directly faces the pattern of the printed wiring board (1) to be tested for continuity, and around it is a through-hole pad that connects with the contact probe. and its leader line.

In this regard, according to the conventional method, as shown in the plan view of FIG. Limited by the size of the connector, the size of the connector, and K, normally only about 50 pads can be provided, and as the number of pads is restricted, the printed wiring board to be inspected has a complex circuit and is denser. The drawback was that it was not possible to conduct conductivity tests.

In contrast, according to the method of the present invention, as shown in the plan view of FIG. ,
Moreover, pads for contact probes are provided not only at both ends of this jig circuit board, but also in all blank areas other than the detection end of the circuit board, and the number of contact probe pads can be significantly increased, thereby increasing the degree of freedom in patterning. Accordingly, the printed wiring board to be tested for electrical conductivity may have a high-density and complicated pattern, and the presence or absence of disconnections or short circuits in the pattern of the wiring board can be tested very easily and quickly. This is achieved by fixing the contact probe to a metal plate via an insulating plate instead of a conventional connector, and by attaching it to the insulating plate (4) using an extremely easy-to-install fixture (7) in advance.
This is because the contact probe pad can now be provided at any location other than the pattern detection end of the jig circuit board. In addition, it has become possible to easily and quickly electrically connect the contact probe and the contact probe pad on the jig circuit board without using a time-consuming electrical connection method such as soldering. It is something.

Note that a normal printed circuit board, ceramic board, etc. can be used as the test jig circuit board. In addition to the normal printed circuit board, the board to be inspected can be a flexible printed board, a multilayer printed circuit board, a ceramic board, or the like. The thickness of the base material is not particularly limited.

Next, in FIG. 3, (3) is an anisotropic conductive rubber sheet-like material, and a commercially available product can be used.

When this conductive rubber sheet-like material is pressed from both sides, a portion thereof develops conductivity.

That is, by energizing the contact probe, current can be passed through the circuit board of the test jig circuit board through the conductive rubber sheet, and this is the principle of the present invention. It is a characteristic.

By using the printed wiring board inspection apparatus of the present invention configured in this way, it is possible to easily and quickly inspect whether there is a circuit break or a short circuit between circuits.

In other words, the front and back surfaces K of the printed wiring board (1), which is the object to be inspected, and the anisotropically conductive rubber sheet material (3) are remounted, and the contact probe (4) is connected to the insulating plate (5) in advance. This contact probe (4) is fixed to a metal plate (6) and
) The test jig circuit board (2) having the pad (10) corresponding to the pad (10) is clamped and pressurized at a predetermined position of the pressurized test device attached via the fixture (7), and the contact probe is energized. A current flows through the circuit of the printed wiring board through the pad (10) of the jig circuit board, the circuit detection end, and the anisotropic conductive rubber sheet. At this time, if there are disconnections or short circuits in this circuit, these can be inspected simply, quickly, and accurately.

As described above, according to the present invention, there is an advantage that the patterns of various circuit boards such as printed wiring boards having high-density and complicated circuits can be easily and quickly inspected for disconnections and short circuits.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of a conventional testing device, za is a cross-sectional view of a testing device of the present invention, FIG. 4 is a plan view of a conventional testing jig circuit board, and FIG. 5 is a sectional view of a conventional testing device. FIG. 2 is a plan view of an inspection jig circuit board of the present invention. (1)--...Printed wiring board, (2)...
・・・・・・Inspection jig circuit board, (3)・・・・・・
... Anisotropic conductive sheet material, (4) ...
・Contact probe, (5)・・・・・・・・・Insulation plate, (
6)・・・・・・・・・Metal plate, (7)・・・・・・・・・
...Mounting tool, (8)...Leader line, (9)
......Pattern detection end, (10)...
·····pad. Patent applicant name IBIDEN Co., Ltd. Representative Jun Taga

Claims (1)

[Claims] 1. A printed wiring board to be tested for continuity and a testing jig circuit board are placed directly opposite each other, and a non-directional conductive comb sheet is placed between the printed wiring board and the testing jig circuit board. 1. A method for inspecting a printed wiring board, characterized in that the printed wiring board is inspected for breakage of turns or short circuits between patterns on the printed wiring board by sandwiching objects, pressurizing them, and energizing them. 2. A testing jig circuit board is provided for pressing a non-directional conductive rubber sheet on both the front and back surfaces of the printed wiring board to be tested for continuity, and the jig circuit board is connected to at least a pattern for external extraction. A contact probe pad is provided, and the external extraction 1< turn is formed on the surface of the jig circuit board, and the wiring end of the printed wiring board and the test end of the test jig circuit board are directly opposed to each other. A printed wiring board inspection device comprising an insulating plate having contact probes fixed thereon interposed between a metal plate and an inspection jig circuit board.